The Fleetguard Air Breather is a desiccant filter for use on bulk fluid storage tanks. Desiccant breathers are designed to replace standard tank-installed vents and filters during system operation and shutdown, according to the company. Composed of silica gel beads, polyurethane foam, and high-efficiency media, desiccant air breathers work to capture moisture and other harmful contaminants in fluid tanks from particle intrusion.